Container formed of corrugated board



May 5, 1959 y Filed Oct. 22, 1955 J. c. BRACKETT ET AL 2,885,138

CONTAINER FORMED oF coRRUGATED BOARD 2 Sheets-Sheet 1 @if l INVENTOR John C. Brac/reti' Reyno/ds 60W/f "7x ORNEY May 5, 1959 J. c. BRACKETT ET AL CONTAINER FORMED oF CORRUGATED BOARD 2 Sheets-Sheet 2 Filed Oct. 22. 1955 v INVENTOR dal?" C' Bracke t? eyno yf BY {20M/@m am" gvy CONTAINER FORMED F CORRUGATED BOARD John .C. Brackett and Reynolds Guyer, St. Paul, Minn., asslgnors to Waldorf Paper Products Co., Ramsey County, Minn., a corporation of Minnesota Application October 22, 1953, Serial No. 387,589

3 Claims. (Cl. 229-14) This invention relates to an improvement in containers and deals particularly with containers formed of corrugated board.

For many years cartons have been constructed of corrugated cardboard. This board is provided with a pair of flat liners having a corrugated inner member adhered to the inner surfaces of the sheets. Various means of strengthening this board have been employed. For example, the use of duplex corrugated board having two corrugated members interposed between three ilat liners has become commonplace. In such an arrange.- ment there is usually a central web or liner between the two corrugated members and two outer liners overlying the corrugations on veach side of the central web. How. ever, such a structure has a thickness of substantially twice the normal corrugated board and this added thickness is sometimes disadvantageous.

In making containers from corrugated board it is usual practice to form a body in tubular closing il-aps hingedly connected to the upper and lower edges of the side walls. As a result the top and bottom of each container formed is possessed of two to four thicknesses of corrugated board while the side walls are of single thickness, therefore, it is of advantage to strengthen the side walls but normally unnecessary to strengthen the top and bottom of such a container. It is an object of the present invention to accomplish this result at a minimum of added expense.

A feature of the present invention lies in the provision of a corrugated `board having a single liner on each ,side of the corrugated medium and of forming the corrugation medium of two thicknesses of paper board. These layers are adhered together and as a result the corrugated board formed is considerably stronger than where a single sheet is corrugated. In eifect the two sheets which are adhered together and corrugated from a pasted sheet, which is normally of greater strength than a single sheet of equal thickness, the adhesive normally stiffens the material and greatly strengthens the board particularly where the two corrugated sheets are continuously adhered.

A further feature of the present invention resides in the fact that the vsecond thickness of corrugation medium may be added to only those parts of the board which require reinforcing. For example,V if the added reinforcing sheet extends only the height of the side wall portion of the container, the side walls may be s tiffened and strengthened without unduly strengthening the top and bottom aps. In other words the strength is added where it is required and may be eliminated where it is not required.

It has been found that if the two sheets which are adhered together to form the corrugation medium are adhered just before the sheets pass between the corrugation rollers, the adhesive will not have set sufficiently to interfere with the corrugation operation. If two sheets were adhered together and then at a later time placed between the corrugating rollers considerable strain would be placed upon the sheets tending to tear or split them atent O 2,885,138 Patented May 5, 1959 as the paper is corrugated. However, by applying adhesive to one of the sheets and bringing it in contact Figure 2 is a diagrammatic view of a blank of whichk the container is formed.

Figure 3 is a diagrammatic plan view showingv the,

manner in which two or more containers may be produced, both containers having reinforced Vside Walls.

Figure 4 is a sectional view through the corrugated board after completion.

Figure 5 is a sectional view through the corrugated` board, the position of the section being at right angles to the section shown in Figure 4.

Figure 6 is a diagrammatic view showing the manner in which the corrugated board may be formed.

As indicated in Figure 4 of the drawings the corrugated board A includes a pair of liner sheets 10 and 11 which are flat and parallel and a corrugation medium connect-l ing the sheets 10 and 11. As shown in Figure 4 the co1;- rugation medium ymay include the usual corrugation sheet; 12 and one or more Vauxiliary sheets 13 which are adheredY thereto.

In general the manner in which the corrugated board',

may be -seen -from Figure 6; one liner 10 is un-wound from a supply roller and passes over suitable rolls 14, 1,5, 16, 17, and 19. These rolls may comprise heating.,

ro-lls and -nor-mally change the direction of travel of the sheet so that the liner remains in contact with the rollA a predetermined time. The heated liner then extends around the presser roll 20 which actually causes contact between the liner and corrugation medium.

As is usual practice one corrugation medium which comprises the usual corrugation sheet 12 is drawn from a supply roll 21 and over feed rolls, such as 22, to extend over a corrugated rollerV Y2,3 andl between this roller and the companion corrugating roller 24.

The sheet 13 is drawn from the supply roll 25 and` passed feed rolls such as` 2 6 and also over the glue roll 27 which cooperated with a roll 29 in the glue reservoir 30. Accordingly a iilrn of suitable adhesive is appliedk to one surface of the sheet 13 during its travel.

The sheet A13 -is directed by rollers 31 over the corru.-. gating roller 23 beneath the sheet 12. In other words` the two sheets come together closely adjacent to thev roller 23 and travel between the corrugating rollers Ltogether. As a result both sheets 12 and 13 are corrugated` simultaneously. As the combined sheets travel4 above the surface of the roller 24 adhesive is applied to the sur:A faces of the corrugations by glue wheels 32, oneof which., rotateswithin the glue reservoir.

As the combined sheets 12 and 13 have the liner 1.0. passed between the corrugating roller 24 and the presser roller 20 the liner is adhered to the corrugation mediumI forming single face corrugated board.

The single face corrugation thus formed passes overaconveyor 34 and accumulator 35 and is conducted overy feed rolls suchk :1.5.36 to a glue roll 37 which obtainsglue from the roll 39 rotating in the glue reservoir. Glue is applied to the undersurface of the corrugated board and.-

tothe corrugations ofthe sheet 13.

The liner 11 is stored upon a storage roll 41 and is drawn over preheatng and drive rolls 42 and is applied to the undersurface of the single faced corrugation between pressure rollers 43. The corrugated board then passes between heating and pressure rolls until the ad-K hesive has set suf`n`ciently to complete the board.

When it is desired toprovide reinforcement for a pre- 46L`and 47, which are connected by parallel fold lines 49, 50, and 51. These panels normally `extend longitudinally of the sheet as it comes from thecorrugater. Accordingly parallel lines of fold 52 and 53 are usually provided in the sheet as it travels from theI corrugater, the sheets being cut to the proper length which is approximatel; the total of the width of the panels 44, 45, [46, and A Thaold lines 52 and 53 normally connect the central portion of the sheet with marginal portions which are later slotted to provide closing aps. For example the deps 54.55.56, and 57, are connected to the respective wall panels along the fold line 52 while similar closing naps 59,160,161, and 62, are connected to the respective wall panels along the fold line 53. The various closing flaps fold into superposed relation when the container is closed as is indicated in Figure l of the drawings. The top` and bottom walls of the container are of double thickness and are accordingly stronger than the side walls which are of single thickness. A feature of the present invention resides in the fact that the reinforcing sheet 13 may be applied only to that portion of the sheet which forms the side walls, thus reinforcing the side walls without adding the additional cost of reinforcing the end laps. InFigure 3 of the drawings we show a typical example of the manner iu which two container blanks may be simultaneously formed by a sheet as it leaves the corrugater. The sheet is traveling in the direction of the arrow in this figure. As the sheet nears the end of the corrugater it is slit by any suitable means such as by the slitting wheel 63. This divides the sheet longitudinally into two sheet portions 64 and 65 which may be the same width, or different widths, depending upon the containers to be formed. Each of the portions 64 and 65 is directed to a dierent cutoff mechanism which cuts the sheet into proper lengths. These lengths are normally unequal but may, of course, be equal if desired.

The sheet portion 64 also passesbetween creasing rollera 66 which crease the sheet portion 64 longitudinally to form longitudinal creases such as 52 and 53. The sheet portion 65 also passes between creasing rollers 67 which longitudinally creases the sheet to form creases auch as 52 and 53. The sheets thus formed are passed through creasing and slotting devices which produces the crease lines 49, 50, and 5l, and the slots separating the various closing flaps.

As shown in Figure 3 the reinforcing sheet113 which is embodied within the portion `64 is approximately the width of the distances between the crease lines. In actual practice the sheet 13 extends slightly beyond the creases 52 and 53 to allow for slight misalignment of the sheet and to insure strength in the top and bottom longitudinal creases 52 and 53.

The sheet 13 which reinforces the sheet portions 65 is also usually slightly wider than the distance between the creasing rollers 67. In such a case there are two supply rollers 25 arranged on the same or different shafts and properly spaced so as to extend through the desired area of the sheet. i

As a result of this arrangement it will be noted that the side walls of the container which contain the corrugated sheets 12 and 13 are reinforced and substantially the fact that the combined adhesive strengthens the sheet in the same way that the laminated sheet is usually stronger than a single sheet of equal thickness.v

If preferred the reinforcing sheets 13 may extend the full width of the corrugater. However, it is usually unnecessary to reinforce the portions of the sheet which form the closing flaps and `obviously a `considerable saving in paper results.

In the production of corrugated blanks for making containers the corrugater must be stopped long enough to change the position of the creasing rollers and cutoff mechanism in changing from one length to another. While this stopping of the machine is for an extremely short period of time due to thefact that the machine `is often providedwith creasing rollers which may be preset while the machine is in operation, the time interval is sufficiently long to ,permit a change in the width or arrangementof the sheets 13 at the beginning end of the corrugater in operation.

In accordance with the patent statutes, we have de scribed the principles of construction and operation of an improvement in containers, and while we have endeavored to set forth the best embodiment thereof, we desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of our invention.

We claim:

l. A container blank formed or corrugated board, the blank including four hingedly connected wall panels, closing flaps hingedly connected to said wall panels, the portion of the corrugated board forming said panels including a pair of parallel liners and a corrugated medium therebetween and connected thereto, the corrugated medium being `composed of a plurality of layers of paper board, the end flaps being formed by parallel liners and a single thickness corrugated medium therebetween.

2. A corrugated sheet having a pair of generally parallel liners and a corrugated medium therebetween and adhered thereto, the corrugated medium being composed to two thicknesses of paper board along an intermediate portion thereof, the marginal edge portion which is at right angles to the flutes of the corrugations being composed of a single thickness of paper board in the corrugated medium.

3. A container including rectangularly arranged side and end walls hingedly connected` together and closing flaps articulated thereto along opposite edges thereof, the container being formed of corrugated board having vertically extending flutes, the flutes of the side walls being formed of two thicknesses of paper board and the flutes of at least a portion of the closing flaps being formed of a single thickness of paper board.

'References Cited in the file of this patent UNITED STATES PATENTS 1,100,065 Penes June 16. 1914 1,119,146 Ferres Dec. l, 1914 1,410,622 Swift Mar. 28, 1922 1,425,914 Swift Aug. 15, 1922 1,600,396 Campbell et al. Sept. 2l, 1926 2,455,124 Johnson Nov. 30, 1948 2,689,079 Timer Sept. 14, 1954 FOREIGN PATENTS` 214,797 `Great Britain May l, 1924 

